1 pkg. chocolate cake mix
1 (8 oz.) pkg. cream cheese, softened
2 tbsp. butter, softened
1 tbsp. cornstarch
1 (14 oz.) can sweetened condensed milk (not evaporated milk)
1 egg
1 tsp. vanilla

Preheat oven to 350 degrees. Prepare cake mix as package directs. Pour batter into well-greased and floured 10-inch bundt pan. In small mixer bowl, beat cheese, butter and cornstarch until fluffy. Gradually beat in sweetened condensed milk, then egg and vanilla until smooth. Pour evenly over cake batter. Bake 50-55 minutes or until toothpick comes out clean. Cool 10 minutes. Remove from pan. Store covered in refrigerator.